High-speed non-intrusive measurements of fuel velocity fields at high-pressure injectors
High-speed non-intrusive measurements of fuel velocity fields at high-pressure injectors
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DOI：
10.1016/j.optlaseng.2016.10.003
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发表时间：
2017-03
影响因子：
4.6
通讯作者：
Johannes Gürtler;Raimund Schlüßler;A. Fischer;J. Czarske
中科院分区：
文献类型：
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作者：
Johannes Gürtler;Raimund Schlüßler;A. Fischer;J. Czarske
提出了一种利用单台高速摄像机和调频激光器快速测量喷雾流场的新方法。速度范围从零到几百米/秒，这需要高测量速率和大动态。通常，流量测量需要将示踪剂颗粒播种到流体。一个范式转移到播种免费测量。评估在流体液滴的相边界处散射的光。为了验证高速测量系统，详细的不确定性分析是通过测量以及模拟。因此，基于高时间速度梯度的散射光强度的变化被发现是对不确定性的主要贡献。在500 kHz的测量速率下获得的最终测量结果在不到1 ms的时间内显示了从0 m/s到400 m/s的喷雾速度，并且实现了在几μs的特征时间内检测不稳定和不规则流动现象。这表明所提出的高速测量系统具有高测量速率、高时间分辨率和大测量范围。
Using a single high-speed camera and a frequency modulated laser, a novel approach is presented for fast velocity field measurements in unsteady spray flows. The velocity range is from zero up to several 100 m/s, which requires a high measurement rate and a large dynamic. Typically, flow measurements require to seed tracer particles to the fluid. A paradigm shift to seeding-free measurements is presented. The light scattered at the phase boundaries of the fluid droplets is evaluated. In order to validate the high-speed measurement system, a detailed uncertainty analysis is performed by means of measurements as well as simulations. Thereby, variations of the scattered light intensity, which are based on the high temporal velocity gradients, are found to be the main contribution to the uncertainty. The eventually measurement results, obtained at a measurement rate of 500 kHz, exhibit spray velocities ranging from 0 m/s up to 400 m/s in less than 1 ms, and the detection of unsteady and irregular flow phenomena with a characteristic time of several μs is achieved. This demonstrates the high measurement rate, the high temporal resolution and the large measurement range of the proposed high-speed measurement system.